44 A TEXT-BOOK OF GRASSES 
in spite of its good qualities, it is looked upon as a per- 
nicious weed. It is not wise to introduce this species on 
land that is free from it. A meadow should be a part of a 
rotation, and Johnson-grass does not readily give up its 
place to the following crop. When a permanent meadow 
is desired, this grass, if its weedy habit be not taken into 
consideration, is probably the best for the purpose in 
those parts of the South, such as the black soil of central 
Texas, where it reaches its highest development. It is 
less satisfactory as a pasture-grass since, not well with- 
standing grazing, the yield decreases after two or three 
years. If a farm is already infested with Johnson-grass 
it is well to take advantage of its useful qualities as a 
meadow-grass. As this species tends to become sod-bound 
in a few years owing to the rapid multiplication of root- 
stocks, the field should be plowed every two or three years. 
50. Eradication of Johnson-grass—Johnson-grass can 
be eradicated, but the process requires more care than in 
the case of most weeds. Plowing in the fall with a turn- 
ing plow, harrowing out and removing the rootstocks, 
sowing the field to early-maturing grain, oats or rye, 
cut for hay in the spring, and following with a cultivated 
crop, will keep the grass in subjection. In the region where 
Johnson-grass reaches its greatest development, alfalfa 
also thrives. Hence an excellent method to utilize an 
infested field is to sow alfalfa. This is done in the fall 
after the field has been plowed and harrowed to remove 
the rootstocks. The alfalfa soon smothers out most of 
the Johnson-grass, and the hay is not injured by the pres- 
ence of such of the latter as may remain. Johnson-grass 
shares with sorghum the tendency to poison stock through 
the production, under certain conditions, of hydrocyanic 
acid. (See Farmers’ Bulletin No. 279.) 
